Biomedical subjects

Franco Merlo

Publications and source records attributed to Franco Merlo.

5 recordsLinked to original sources

PubMed2005

The use of S-phenylmercapturic acid as a biomarker in molecular epidemiology studies of benzene.

S-Phenylmercapturic acid (S-PMA), is a urinary metabolite of benzene, thought to be derived from the condensation product of benzene oxide with glutathione. S-PMA may be determined by GC, HPLC (UV or fluorescence detection), GC-MS, LC-MS/MS or immunoassays. The limit of sensitivities of most of these techniques is 1 microg/l urine or below. It has been suggested that S-PMA may have value as a biomarker for low level human exposure to benzene, in view of the facts that urinary excretion of S-PMA has been found to be related to airborne benzene in occupationally exposed workers, and that only low background levels of S-PMA have been found in control subjects. We have evaluated the use of S-PMA as a biomarker, using a commercially available analytical service, in a multicentre European study of populations exposed to varying levels of benzene, in Italy (Milan, Genoa) and in Bulgaria (Sofia). These were filling station attendants, urban policemen, bus drivers, petrochemical workers and referents (a total of 623 subjects). S-PMA was measured at the end of the work shift by an immunoassay procedure. Urinary benzene (in Milan only) and the benzene metabolite trans,trans-muconic acid (t,t-MA) were measured before and after the work shift. Air-borne benzene was measured as a monitor of exposure. Urinary benzene was the most discriminatory biomarker and showed a relationship with airborne benzene at all levels of exposure studied (including groups exposed to <0.1 ppm benzene), whereas t,t-MA and S-PMA, as determined by immunoassay, were suitable only in the highest exposed workers (petrochemical industry, geometric mean 1765 microg/m3 (0.55 ppm) benzene). All three biomarkers were positively correlated with smoking as measured by urinary cotinine).

Acetylcysteine↗

PubMed2005

The last three months of life of Italian cancer patients. Methods, sample characteristics and response rate of the Italian Survey of the Dying of Cancer (ISDOC).

STUDY OBJECTIVE: The Italian Survey of the Dying of Cancer (ISDOC) was undertaken to evaluate the experiences of Italian people dying from cancer during their last three months of life in all settings of care. STUDY DESIGN: A two-stage probability sample was used to estimate end-of-life outcomes of about 160 000 Italian cancer deaths. In the first stage, 30 of the 197 Italian Local Health Districts (LHD) were randomly selected after stratification. In the second stage, a fixed proportion of cancer deaths was randomly drawn from each LHD, and 2000 death certificates of patients who died of cancer were identified. The non-professional caregivers were identified and interviewed using a semi-structured questionnaire derived from the Views of Informal Carers--Evaluation of Services (VOICES). RESULTS: Caregivers were successfully identified for 95% of the sample (n=1900). The caregiver was the child (42.7%), the spouse (36.5%), another family member (17.3%), or a friend (1.5%). Only 3% of the sample had no non-professional support. An interview was obtained for 1289 (64.5%) of the sample, at a median time of 234 days after death (range: 103-374). Higher response rates were associated with home death (67.7%) and with a higher education (>70%). Conversely, a lower response rate was observed when the caregiver was the spouse (56.2%). Response rates ranged from about 80% for letters sent four to six months after the patients' death to about 60% for letters sent after eight months or more. A descriptive analysis of refusals, based on the transcripts of the telephone calls, allowed classification of 61% of refusals for at least one of the two dimensions examined: caregiver psychological suffering and quality of care received by the patient. Psychological suffering was present in 99% of refusals examined for this dimension (48%). Conversely, a poor quality of care was reported by 63% of the refusals examined for this dimension (23%). CONCLUSION: The ISDOC survey provides a representative picture of the needs and problems associated with the last three months of life of Italian cancer patients.

Adult↗

PubMed2003

Micronuclei frequency in children exposed to environmental mutagens: a review.

Cytogenetic monitoring has been traditionally used for the surveillance of populations exposed to genotoxic agents. In recent years sensitivity problems emerged in surveys of populations exposed to low levels of mutagens, and therefore alternative approaches have been explored. Biomonitoring studies in children are a promising field, since because of evident differences in the uptake, metabolism, distribution and excretion of mutagens this population seems to be more susceptible than adults. Further, the effect of major confounders such as cigarettes smoking, occupation, life-style, and dietary factors plays a minor role. Among cytogenetic assays, the micronucleus assay (MN) has several advantages and is increasingly used. A review was then carried out to synthesize the published data on the occurrence of MN in children and adolescents (age range 0-18 years), and to assess the impact of genotoxic exposure on MN frequency. Overall, 20 papers from international literature and 8 Russian papers were included. An effect of age was found within this age range, while the influence of gender on MN frequency was irrelevant. These results were confirmed by the re-analysis of data for 448 children selected from the HUMN database. An effect of chronic and infectious diseases on MN levels has been reported by various authors. Most studies describing the effect of exposure to genotoxic agents (ionizing radiation, chemicals, drugs, environmental tobacco smoke) found an increase of MN in exposed children. The limited number of published papers indicates that the conduct of properly designed studies on the effect of environmental pollutants in children may be difficult. This review confirmed the usefulness of MN assay in biomonitoring studies conducted in children, revealing that in many circumstances investigating children increases the sensitivity of the study, even with low dose exposures.

Child↗

PubMed2003

Simian virus 40 and malignant mesothelioma (Review).

Simian virus 40 (SV40) was recognized as a contaminant of early poliovirus vaccines that were provided to millions of individuals in Europe and in the USA between 1955 and 1963. SV40, a DNA virus of the family of papovaviridae, was proven to be oncogenic in rodents and able to transform human and animal cells in vitro. In 1993 SV40 was accidentally discovered to produce mesotheliomas in hamsters when it was injected in visceral cavities. Afterwards, SV40 DNA sequences were detected with significative frequency in human pleural mesotheliomas by using polymerase chain reaction (PCR) and then SV40 DNA oncogenicity was associated with its large T antigen (Tag). This finding was confirmed by many laboratories, while a few research groups failed to replicate these data and argued that the SV40 DNA detection might be a PCR contamination artefact. In this review the dispute is examined in the light of recent experiments performed to identify molecular and cellular aspects of carcinogenicity and/or co-carcinogenicity of SV40 in human mesothelioma.

Animals↗

PubMed2002

[Prostatic tumor: how many biopsies?].

INTRODUCTION: Ultrasound-guided prostatic biopsy is usually performed by sextants according to Hodge, but the authors feel that 6 biopsies are insufficient. It has been suggested that the number of prostatic biopsies be increased and the mapped areas extended, but this causes discomfort to patients and increases effective costs. The authors suggest repetition of biopsies in "risk" cases, routinely selecting patients taking into account the best cost-benefit ratio. MATERIALS AND METHODS: From January 2000 to December 2001, 682 first series biopsies were performed on as many patients. A Stamey modified sextant technique was used: 6 biopsies, 3 on each side carried out more posterolaterally than the original technique. The biopsy procedure was repeated within 4 months in 11 patients with high risk clinical parameters (PSA > 10 or high PSA and prostatic nodule). During the period of observation, 25 patients had over 0.75 ng/year increase in their PSA and so biopsies were repeated. RESULTS: After the first biopsy series, 277 were positive. Of the 11 repeated biopsies, 3 were positive. Of the 25 patients with altered PSA velocity, 9 were positive. DISCUSSION AND CONCLUSIONS: It has been shown that only 10-12% of biopsies are false negative in the sextant biopsy series when taken posterolaterally. The techniques that increase the number of biopsies have around 3-5% false negatives, but this involves more discomfort for the patient, local anaesthesia and a possible increase in complications. The procedure whereby biopsies were only repeated in patients with high risk clinical elements, saved 3852 biopsies from being carried out, with an economic saving (just on the histological exam that was not carried out) assessed at 59.681,80 Euro (115,560,000 Lire) for our Local Health Service.

Biopsy↗